COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Growth Analysis of a Patient with
Ectodermal Dysplasia Treated with
Endosseous Implants: A Case Report
Karin B. Becktor, DDS1/Jonas P. Becktor, DDS2/Eugene E. Keller, DDS, MSD3
Congenital absence of multiple teeth and poorly developed alveolar ridges are associated with ectodermal dysplasia. Affected patients often require dental prosthetic treatment during their developmental years. Maxillofacial growth and development in a preadolescent female patient with ectodermal
dysplasia following oral rehabilitation with maxillary and mandibular endosseous dental implants is
reported. Four maxillary and 4 mandibular implants were successfully integrated and restored at 8
years of age. Growth analysis 12 years later revealed that the implants followed maxillary and
mandibular growth displacement. Minor impaction of the maxillary implants was observed, and
mandibular implants were affected by the mandibular growth rotation, which led to a change in
implant inclination. The treatment outcome is compared to similar previously reported studies and
cases. (INT J ORAL MAXILLOFAC IMPLANTS 2001;16:864–874)
Key words: craniofacial growth, ectodermal dysplasia, endosseous dental implants
E
ctodermal dysplasia represents a group of
inherited conditions that adversely affect ectodermal structures such as hair, skin, nails, and teeth.
The frequency of hypohidrotic ectodermal dysplasia
(HED) is about 1/100,000.1 Congenital missing primary and permanent teeth in the maxilla and
mandible and associated hypoplasia of the alveolar
bone are the most frequently described oral abnormalities.2 The number of missing teeth varies, with
a higher incidence in the mandible. When present,
1
Visiting Clinician, Division of Orthodontics, Dental Specialties,
Mayo Clinic, Rochester, Minnesota; PhD Candidate, Department
of Orthodontics, School of Dentistry, University of Copenhagen,
Denmark.
2Visiting Clinician, Department of General Surgery, Division of
Oral and Maxillofacial Surgery, Mayo Clinic, Rochester, Minnesota; Senior Registrar, Department of Oral and Maxillofacial
Surgery, Länssjukhuset, Halmstad, Sweden.
3Consultant, Department of General Surgery, Division of Oral and
Maxillofacial Surgery, Mayo Clinic, and Professor, Mayo Medical
School, Rochester, Minnesota.
Reprint requests: Dr K. B. Becktor, Department of Orthodontics,
School of Dentistry, Faculty of Health Sciences, University of
Copenhagen, 20 Nørre Allé, DK-2200 Copenhagen N., Denmark.
Fax: +45-35-326505. E-mail: [email protected]
864
Volume 16, Number 6, 2001
teeth are frequently deformed; crowns are conical
and taurodontism (prism-shaped molars with large
pulp chambers) is common. In the maxilla, the most
frequently existing primary teeth are second molars,
canines, and central incisors; in the permanent dentition, first molars, canines, and central incisors are
the most commonly present. In the mandible, primary canines followed by permanent canines and
first molars are the most frequently present.2 The
etiology for this type of dental agenesis is dysplasia
of the oral epithelium.3
Clinical management of oligodontia presents
many problems for the restorative dentist. Removable partial or complete dentures have been proposed
as the treatment of choice in the affected growing
individual. Currently, endosseous dental implants are
considered the ideal reconstruction modality following completion of alveolar growth and development.
A retentive and stable removable partial or complete
denture in preadolescent ectodermal dysplasia
patients is difficult to achieve because of the absence
of alveolar bone and continuous changing of maxillary and mandibular basal bone relationships. To
avoid functional and/or psychosocial compromise,
early treatment with dental endosseous implants is a
worthy goal in these patients.
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
The treatment outcome in a female patient with
hypohidrotic ectodermal dysplasia and oligodontia
was analyzed 12 years after the placement of
endosseous dental implants in the posterior maxilla
and anterior mandible at age 8.
PATIENT HISTORY
The patient was a female, the third child of parents
of unknown genetic background. She was born as a
“normal” infant at term weighing 7 lbs, 4 oz after a
normal pregnancy. One male and one female sibling
were described as normal. The mother had experienced spontaneous miscarriage on 2 occasions. In the
neonatal period, the mother noticed that the child
was sweating very little and was heat-intolerant. Academic progress was judged to be normal, and the
patient’s health in general was described as excellent.
Physical Examination
A comprehensive examination of the patient at age
8 years, 7 months was undertaken at the Mayo
Clinic (Rochester, MN) by a multidisciplinary team
that included representatives from oral and maxillofacial surgery, prosthodontics, dermatology, and
genetics.
Physical Appearance. The patient had diffusely
sparse head hair, eyebrows, and eyelashes, and no
patches of alopecia (loss of hair). She had severe
hypohidrosis (diminished sweating), dry skin, and
dyschromasia (abnormal pigmentation) in the
orbital region. The nails were normal and the girl
was otherwise healthy.
Genetics. The father had several congenitally
missing teeth and mild hypohidrosis. The milder
expression in the father, compared to the severe
expression in the daughter, argues strongly against
an x-linked inheritance. Moreover, the patient’s sister had no sign of ectodermal dysplasia. If the pattern of inheritance had been x-linked dominant, at
least some expression in the sister would have been
expected. Therefore, the diagnosis of hypohidrotic
ectodermal dysplasia with autosomal dominant
inheritance was given.
Oral Examination. The patient had severe
oligodontia. The only teeth present were the maxillary primary canines and permanent mandibular
first molars (Fig 1). The canine crowns had a conical shape. The alveolar process in the edentulous
regions was hypoplastic.
Radiologic Investigation
Panoramic Radiographs. Figures 2a to 2d show the
dentition and bone appearance from age 8 years, 7
Fig 1 Dentition at age 8 years. The only developed teeth are
the maxillary primary canines and mandibular first molars.
months to age 20 years. The first molars were taurodontic and the alveolar process was hypoplastic in
all edentulous areas. Vertical alveolar growth
occurred with the development and eruption of the
maxillary canines and mandibular first molars. The
relative vertical position of the maxillary posterior
implants changed relative to the nasal floor (Figs 2b
and 2c), as the result of surface remodeling of the
nasal floor.
Lateral Cephalometric Radiographs. Table 1
shows the craniofacial morphologic analysis, and
the reference points and lines used for analysis are
shown in Fig 3. Before treatment, reduced vertical
face height, a retrognathic maxilla, and lack of alveolar development in the edentulous areas characterized the morphology. After implant placement,
there was mandibular backward (clockwise) rotation
type I, a reduced mandibular plane angle, and an
overall increase in vertical face height (Table 1).
Treatment Objectives
Because of the functional and psychosocial needs of
the patient, dental endosseous implants were considered a reasonable treatment option in spite of her
young age.
Surgical Management
At age 8 years, 8 months, four 10-mm self-tapping
threaded cylindric endosseous implants were placed
in the maxillary left and right canine and first premolar regions. The alveolar process was short and
narrow. Basal bone was present but marginal in
width and height. The 4 Brånemark System
implants (Nobel Biocare, Göteborg, Sweden)
extended into the piriform rim cortex anteriorly and
into the anterior antral cortex posteriorly.
The International Journal of Oral & Maxillofacial Implants
865
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Fig 2a
Orthopantomogram at age 8 years.
Fig 2b Orthopantomogram at age 9 years,
11 months after placement of endosseous
implants.
Fig 2c Orthopantomogram at age 19 years.
Note the eruption of the mandibular first
molars.
Fig 2d Orthopantomogram at age 20 years.
The canines were extracted because of caries
and periodontal bone loss. Four endosseous
implants were placed in the anterior maxilla.
The 8 implants that had been placed 12 years
earlier were still clinically and radiographically
osseointegrated.
866
Volume 16, Number 6, 2001
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Table 1
Craniofacial Cephalometric Analysis
Age
SNA
angle
(deg)
SU*
8 y, 10 mo
9 y, 7 mo
20 y
72.0
71.5
72.0
–2.9
–3.3
–2.9
S-N-Pog
(deg)
78.0
75.0
81.0
A-N-Pog
AN/PP
SN/MP
(deg)
SU* (deg) SU* (deg) SU*
SU*
–0.6
–1.4
–0.3
–6.0
–3.5
–9.0
–3.2
–2.2
–4.4
4.0
3.0
3.5
–1.3
–1.7
–1.5
27.0
39.5
33.5
–1.0
1.1
0.1
Inclination of lower
implant to
N-S-Ba
mandibular
(deg) SU*
plane
131
131
126
0
0
–1.1
—
70.0
68.5
*x–x– = SU (standard units), where x is the observation and x– is the mean.
SD
S = sella; N = nasion; A = point A; Pog = pogonion; SN = sella-nasion line; PP = palatal plane; MP = mandibular plane;
Ba = basion.
Fig 3 (Left) Skeletal reference points and lines. For definitions
see Solow.25 A = point A; Ba = basion; MP = mandibular plane; N
= nasion; Pog = pogonion; PP = palatal plane; S = sella; SN =
sella-nasion line; ANS = anterior nasal spine.
Fig 4 The definitive fixed implant-supported maxillary and
mandibular prostheses at age 20 years.
S
N-SN
Ba
ANS
A
PP
Pog
MP
In the mandible, the alveolar process was also
short and narrow. The basal bone was of typical size
for an edentulous mandible in a nearly 9-year-old
patient. Bone density was normal in both jaws. Four
13-mm standard and one 15-mm standard Brånemark system implants were placed between the
mental foramina. Abutment connection surgery was
performed after 10 months of healing. One nonintegrated mandibular implant was removed.
The patient returned 10 years later at age 19
years for further prosthetic treatment, since the
fixed/removable maxillary prosthesis was unstable
and did not relate well to the fixed mandibular prosthesis. The maxillary canines were extracted
because of horizontal bone loss and caries. Two 10mm and two 13-mm endosseous implants were then
placed in the anterior maxilla and penetrated the
anterior nasal floor cortex. Thirteen months later,
abutment connection surgery was accomplished.
Abutments on the 4 previously placed maxillary
implants were lengthened from 3 to 7 mm.
Prosthetic Treatment
At age 9, the patient was provided with a maxillary
fixed/removable prosthesis supported by the bilateral posterior implants and the anterior canine
teeth. The mandibular prosthesis was of standard
fixed-type fabrication. At age 20 years, fixed
implant-supported prostheses were placed in both
the maxilla and the mandible (Fig 4).
Growth Analysis
Growth analysis from age 9 to 20 years showed that
the implants in both the maxilla and mandible
The International Journal of Oral & Maxillofacial Implants
867
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
9 years old
20 years old
9 years old
20 years old
Fig 5a Superimposition on stable structures in the anterior cranial base from age 9 years to age 20 years.
Fig 5b Maxillary superimposition on stable structures and
endosseous implants during the same period, according to Björk
and Skieller.19 Note relocation of the nasal floor.
9 years old
20 years old
Fig 5c Mandibular superimposition on stable structures and
endosseous implants during the same period.
followed the downward and forward displacement of
the maxilla and mandible (9.1 mm forward in the
maxilla, 17.9 mm in the mandible; Fig 5a). The vertical displacement of the maxilla was only 2 mm, and
the relocation of the nasal floor and maxillary sinus
floor was 3.8 mm, slightly more pronounced anterior
than posterior (Fig 5b), which was the result of the
forward (counterclockwise) rotation (2.5 degrees) of
the maxilla. The mandible rotated forward (counter868
Volume 16, Number 6, 2001
clockwise) 10.5 degrees (Fig 5c), which caused a
change in the inclination of the implants (70 degrees
to 68.5 degrees; Fig 5a). Bone apposition could be
observed inferior to the symphysis (Fig 5c). No
transverse enlargement could be measured posteriorly on models from age 9 to 20 years.
Figures 6a to 6d show the lateral cephalometric
radiographs from ages 8 to 20 years, and Figs 7a to
7d show the patient at ages 8 and 20 years.
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
a
b
c
d
Figs 6a to 6d Lateral cephalometric radiographs at (a) age 8 years, (b) age 9 years, (c) age 19 years, and (d)
age 20 years. Note relocation of the nasal floor from 9 to 19 years and the eruption of the mandibular first
molars.
The International Journal of Oral & Maxillofacial Implants
869
BECKTOR ET AL
Patient at first visit at age 8 years.
Figs 7c and 7d
Patient at age 20 years, 12 years after initial treatment.
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Volume 16, Number 6, 2001
870
Figs 7a and 7b
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Table 2
Authors
Bergendal
et al20
(1991)
Escobar and
Epker21
(1998)
Cronin
et al16
(1994)
Reported Mandibular Endosseous Implants in Growing Patients with Ectodermal Dysplasia
Subjects
(no./sex)
Age
(y)
Mandibular
dentition
1/male
6
Edentulous
2/male
7 and
11
2/female
5
14
Implants
(no./length)
2/10 mm and
2/13 mm
Brånemark
Edentulous
5 Brånemark
(both patients) (both patients)
Partially
edentulous
Partially
edentulous
2
4 patients
edentulous,
2 patients
partially
edentulous
Partially
edentulous
22 (total)
3i and
Brånemark
4/10 mm
Brånemark
6
Kearns
et al17
(1999)
6/male
11.2
(mean)
Davarpanah
et al22
(1997)
Smith
et al23
(1993)
1/male
14
1/male
5
Partially
edentulous
1/13 mm
Brånemark
Guckes
et al24
(1997)
1/male
3
Edentulous
4 IMZ
Region
Follow-up
(y)
Between
4
mental
foramina
Between
5 to 6
mental foramina
(both patients)
First incisor
None
region
Right to left
None
second premolar region
Between
7.8
mental
(mean)
foramina
Between
mental
foramina
Central in the
anterior
mandible
Between
mental
foramina
None
Growth
analysis
No
No
Other
Significant
bone growth
around implants
Significant
bone growth
around implants
No
No
Several
mandibular
teeth extracted
Implants follow Two patients
forward growth had bone grafts;
of mandible
1 implant did
not osseointegrate
No
None
No (done in
(done in
Kearns et al17);
later study) submerged
implant
5
Implants follow
forward growth
of mandible
No angulation
problems
Brånemark: Nobel Biocare, Göteborg, Sweden; 3i: Implant Innovations, Palm Beach Gardens, FL; IMZ: Interpore International, Irvine, CA.
DISCUSSION
Endosseous Implants in Partially
Edentulous Developing Jaws
The use of endosseous implants in the oral rehabilitation of adolescent patients with HED should be
considered a viable treatment option. Opinions vary
as to whether it is advisable to place endosseous
implants in growing patients, since there is a lack of
scientific knowledge concerning the fate of these
implants and associated prosthetic rehabilitation.
Also unknown is what happens psychologically to
these patients when no treatment or various temporary solutions are provided.
The present female patient, who was treated
before puberty with endosseous implants and followed for 12 years, developed well psychologically.
The success achieved in this patient suggests it is
possible to treat patients before puberty with
endosseous implants. Only 1 additional surgical
procedure and 1 prosthesis remake were required
during the 12-year follow-up.
Considerable research supports the efficacy of
rehabilitating a completely or partially edentulous
mandible and maxilla using prostheses supported
by implants.4,5 However, almost all the scientific
investigations have been performed in adults, when
the dynamics of growth and development are not
an issue. Placement of implants in the growing
maxilla and/or mandible that is only missing a few
permanent teeth has been studied, and it has been
demonstrated both clinically 6–8 and experimentally9,10 that ankylosed (osseointegrated) endosseous
implants adjacent to the natural teeth become submerged because of the continued eruption of the
neighboring teeth and associated growth of the
alveolus. A majority of studies have therefore advocated delaying implant placement until skeletal
growth is completed, especially when natural teeth
are present.6,11
The International Journal of Oral & Maxillofacial Implants
871
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Table 3
Reported Maxillary Endosseous Implants in Growing Patients with Ectodermal Dysplasia
Subjects
(no./sex)
Age
(y)
al17
6/male
14
12
12
7
Guckes et al24
(1997)
1/male
3
Authors
Kearns et
(1999)
Maxillary
dentition
Implants
(no./type)
Edentulous
Altogether,
Edentulous
19 3i and
Partially edentulous Brånemark
Partially edentulous
Left and right
canine present
2 IMZ
Region
Follow-up Growth
(y)
analysis
In the anterior
7.7
maxilla (edentulous (mean)
subjects); in the
buccal segments
(partially edentulous
subjects)
Anterior maxilla
5
Other
No
No
No
No
Three oldest
patients had bone
grafts; submerged
implant in the
7-year-old
No
Both implants
submerged
3i: Implant Innovations, Palm Beach Gardens, FL; Brånemark: Nobel Biocare, Göteborg, Sweden; IMZ: Interpore International, Irvine, CA.
Endosseous Implants in Edentulous
or Nearly Edentulous Developing Jaws
Some studies and case reports have described the
placement and follow-up of mandibular endosseous
implants in patients with HED (Table 2), but limited knowledge is available concerning implant
placement in the edentulous or nearly edentulous
growing maxilla (Table 3). Before placing dental
implants in the growing mandible or maxilla, the
clinician should have an understanding of the
growth and development in this region.
Mandibular Growth Considerations and
Endosseous Implants
From a developmental perspective, the mandible
consists of basal bone (body, ramus, and symphysis)
and alveolar bone. Three processes are also present:
condylar, coronoid, and angulus. Björk and
Skieller12 showed in a group of healthy untreated
adolescents that the average forward rotation was 6
degrees during the 6 years around puberty. The
influence of edentulism on mandibular growth is
not well understood. In the congenital edentulous
mandible, it is mainly the alveolar process that
shows pathologic development, because of the lack
of erupting teeth. It has been shown that subjects
with multiple congenital missing teeth, on average,
have forward rotation of the mandible 13 and a
reduced mandibular plane angle.14
In the absence of the restoration of normal function, it is likely that the expression of facial growth
would have been severely affected by the edentulism
seen in this patient. Normal function helps build
and maintain bone mass. Suboptimally loaded bones
atrophy by increasing the remodeling frequency
while inhibiting osteoblast function.15
In the analysis of the present subject, normal
growth of the condyle was demonstrated (Figs 5a
872
Volume 16, Number 6, 2001
and 5c). The cephalometric tracing shows continued
condylar growth, whereby the mandible and the
implants are displaced forward. This finding is consistent with the findings in the studies mentioned in
Table 2. The mandible in the patient under consideration rotated 10.5 degrees forward (4.5 degrees
more than average). The implants were not submerged because of lack of vertical growth of the
alveolar process in the anterior part of the mandible.
It was interesting to see the actual vertical growth in
the molar region, which became more pronounced
because of the forward rotation (Fig 5c).
During mandibular rotation the teeth normally
adapt to the rotation by compensation in eruption
and inclination,12 but because of the osseointegration process, this is not the case for dental implants.
The changed inclination of the implants caused by
the mandibular rotation can be observed on the
superimposition on the anterior cranial base (Fig 5a
and Table 1). The possible problem of changed
inclination of the implants related to mandibular
rotation has been discussed,16 but no documentation
was presented. In the studies shown in Table 2, the
possible change in inclination was mentioned in
only one study, 17 and the authors reported that
inclination of the implants was unchanged; however, the study did not describe the mandibular
rotation pattern of the 6 subjects. Continued vertical eruption of natural teeth and the rotation pattern of the mandible therefore seem to be the limiting factors for placing implants in the growing
mandible.
In the edentulous or nearly edentulous mandible,
as in the presented subject, where the present teeth
were not in proximity with the implants, the only
change in the implant position would be the inclination. This can be compensated for by revising the
prosthesis.
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
The surface remodeling of the mandibular plane
normally associated with mandibular rotation18 did
not have a negative influence on the implants, since
apposition occurred inferior to the symphysis and
resorption took place at the angulus border (Fig
5c). This is the typical remodeling pattern of forward rotating mandibles.18 Transverse growth in
the anterior region ceases early (before 1 year of
age)18 and is therefore not influenced.
Maxillary Growth Considerations and
Endosseous Implants
Maxillary growth is much more complex than
mandibular growth, and the end result of an
osseointegrated implant placed during growth is
difficult to predict. Maxillary growth occurs as a
result of both passive displacement and enlargement.18,19 Passive displacement occurs as the maxilla
is carried downward and forward by growth and
flexion of the cranial base and a complicated system
of sutures in the midface.18 Maxillary enlargement
occurs in vertical, sagittal, and transversal dimensions.
• Vertical Enlargement. The increase in maxillary
height takes place by growth in the alveolar
process in association with dental eruption. In
connection with the vertical growth, the hard
palate is remodeled, the upper surface is
resorbed, and apposition takes place on the lower
aspect of the hard palate and alveolar process.
This remodeling enables additional enlargement
of the nasal cavity, which is not possible by inferior repositioning of the maxilla alone.18 Implant
studies18 indicate that this relocation increases
when the sutural lowering is diminished.
• Sagittal Enlargement. Growth in the length of the
maxilla is known to occur suturally toward the
palatine bone and by apposition on the maxillary
tuberosities. From early infancy, all sagittal
enlargement originates from the posterior part of
the maxilla.18
• Transversal Enlargement. Growth in the midpalate suture is the most important factor in
transversal enlargement. The posterior part of
the maxilla enlarges 3 1⁄2 times as much as the
anterior part.19 Rigid connection over the midline should therefore be avoided.
In a recent study, 8 the use of implants in the
growing maxilla was discouraged. However, a few
reports concerning endosseous implants in the
growing edentulous or nearly edentulous maxilla
can be found in the common databases (Table 3).
In the 2 subjects (Table 3) in whom the implants
submerged, 17,24 the implants were placed in the
vicinity of natural teeth, and the subjects were only
age 3 and 7 years, respectively. In the remaining 3
subjects 17 and in the present subject, severe
impaction was not encountered. This is the result of
the relative lack of vertical growth of the edentulous
alveolar process. The amount of vertical growth
that is associated with tooth eruption can be
observed in connection with eruption of the canines
(Fig 5b).
Severe impaction of osseointegrated dental
implants in the maxillary alveolus in connection
with remodeling of the nasal floor and hard palate
has been pointed out by Cronin and Oesterle.8 It
was postulated that implants in the alveolus of a
young, growing maxilla may become significantly
buried in bone and their apical portions exposed as
the nasal floor and maxillary sinuses remodel. The
effect of remodeling in the presented subject can be
seen on the maxillary superimposition (Fig 5b).
Björk and Skieller19 showed an average nasal floor
remodeling of 4.6 mm in boys aged 4 to 20 years.
The inferior repositioning related to surface remodeling in the present patient was 3.8 mm.
Because the continuous lengthening of the maxilla occurred posterior to the implants, the implants
moved in harmony with the sagittal displacement
and growth of the maxilla (Fig 5a). No transverse
enlargement could be registered in the tuberosity
region of models from age 9 to 20 years. By not
rigidly connecting the right and left implants, interference at the midline growth suture could possibly
be avoided.17
CONCLUSIONS
In growing individuals, edentulism can become a
functional or cosmetically disabling condition. The
literature and this case report suggest that
endosseous implants can be placed with a good
prognosis in the edentulous or nearly edentulous
growing maxilla or mandible, provided the
mandibular implants are placed anterior to the mental foramen.
In the mandible, only the rotation had an effect
on the implants by changing their angulation. To
the authors’ knowledge, submerged implants have
not been reported in the edentulous mandible, provided they are not placed close to natural teeth. In
the growing edentulous maxilla, a certain amount of
impaction must be expected because of relocation of
the nasal floor and the maxillary sinuses. The
amount of relocation can be evaluated only by maxillary superimposition, as demonstrated in this
The International Journal of Oral & Maxillofacial Implants
873
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
investigation.
Variation in growth from individual to individual
and the difficulties in predicting the amount and
direction of growth should be considered, but caution must be exercised in generalizing the results. A
multidisciplinary approach for oral and maxillofacial
rehabilitation of these patients is recommended.
REFERENCES
1. Airenne P. X-linked hypohidrotic ectodermal dysplasia in
Finland. A clinical, radiographic and genetic study. Proc
Finn Dent Soc 1981;77(suppl 1-3):1–107.
2. Levin LS. Dental and oral abnormalities in selected ectodermal dysplasia syndromes. Birth Defects 1988;24:205–227.
3. Kjaer I, Kocsis G, Nodal M, Christensen LR. Aetiological
aspects of mandibular tooth agenesis—Focusing on the role
of nerve, oral mucosa, and supporting tissues. Eur J Orthod
1994;16:371–375.
4. Adell R, Lekholm U, Rockler B, Brånemark P-I. A 15-year
study of osseointegrated implants in the treatment of the
edentulous jaw. Int J Oral Surg 1981;10:387–416.
5. Adell R. Clinical results of osseointegrated implants supporting fixed prostheses in edentulous jaws. J Prosthet Dent
1983;50:251–254.
6. Thilander B, Odman J, Grondahl K, Friberg B. Osseointegrated implants in adolescents. An alternative in replacing
missing teeth? Eur J Orthod 1994;16:84–95.
7. Thilander B, Odman J, Jemt T. Single implants in the upper
incisor region and their relationship to the adjacent teeth.
An 8-year follow-up study. Clin Oral Implants Res 1999;10:
346–355.
8. Cronin RJ Jr, Oesterle LJ. Implant use in growing patients.
Treatment planning concerns. Dent Clin North Am 1998;
42:1–34.
9. Thilander B, Odman J, Grondahl K, Lekholm U. Aspects on
osseointegrated implants inserted in growing jaws. A biometric and radiographic study in the young pig. Eur J
Orthod 1992;14:99–109.
10. Odman J, Grondahl K, Lekholm U, Thilander B. The effect
of osseointegrated implants on the dento-alveolar development. A clinical and radiographic study in growing pigs. Eur
J Orthod 1991;13:279–286.
874
Volume 16, Number 6, 2001
11. Iseri H, Solow B. Continued eruption of maxillary incisors
and first molars in girls from 9 to 25 years, studied by the
implant method. Eur J Orthod 1996;18:245–256.
12. Björk A, Skieller V. Facial development and tooth eruption.
An implant study at the age of puberty. Am J Orthod 1972;
62:339–383.
13. Sarnas KV, Rune B. The facial profile in advanced hypodontia: A mixed longitudinal study of 141 children. Eur J
Orthod 1983;5:133–143.
14. Nodal M, Kjaer I, Solow B. Craniofacial morphology in
patients with multiple congenitally missing permanent teeth.
Eur J Orthod 1994;16:104–109.
15. Graber T, Vanarsdall RL. Orthodontics: Current Principles
and Techniques. St Louis: Mosby-Year Book, 1994:211.
16. Cronin RJ Jr, Oesterle LJ, Ranly DM. Mandibular implants
and the growing patient. Int J Oral Maxillofac Implants
1994;9:55–62.
17. Kearns G, Sharma A, Perrott D, Schmidt B, Kaban L, Vargervik K. Placement of endosseous implants in children and
adolescents with hereditary ectodermal dysplasia. Oral Surg
Oral Med Oral Pathol Oral Radiol Endod 1999;88:5–10.
18. Björk A. Käkarnas tillväxt och utvekling i relation till kraniet
i dess helhet. In: Forlaget for Faglitteratur (ed). Nordisk
Klinsk Odontologi, ed 1. Copenhagen: Forlaget for Faglitteratur, 1964:1–44.
19. Björk A, Skieller V. Growth of the maxilla in three dimensions as revealed radiographically by the implant method. Br
J Orthod 1977;4:53–64.
20. Bergendal T, Eckerdal O, Hallonsten AL, Koch G, Kurol J,
Kvint S. Osseointegrated implants in the oral habilitation of
a boy with ectodermal dysplasia: A case report. Int Dent J
1991;41:149–156.
21. Escobar V, Epker BN. Alveolar bone growth in response to
endosteal implants in two patients with ectodermal dysplasia. Int J Oral Maxillofac Surg 1998;27:445–447.
22. Davarpanah M, Moon JW, Yang LR, Celletti R, Martínez
H. Dental implants in the oral rehabilitation of a teenager
with hypohidrotic ectodermal dysplasia: Report of a case. Int
J Oral Maxillofac Implants 1997;12:252–258.
23. Smith RA, Vargervik K, Kearns G, Bosch C, Koumjian J.
Placement of an endosseous implant in a growing child with
ectodermal dysplasia. Oral Surg Oral Med Oral Pathol
1993;75:669–673.
24. Guckes AD, McCarthy GR, Brahim J. Use of endosseous
implants in a 3-year-old child with ectodermal dysplasia:
Case report and 5-year follow-up. Pediatr Dent 1997;19:
282–285.
BECKTOR ET AL
COPYRIGHT © 2001 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE
REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
25. Solow B. The pattern of craniofacial associations. Acta
Odontol Scand 1966;24:21–44.
875
The International Journal of Oral & Maxillofacial Implants